Scotland quartet miss training
Scotland centre Graeme Morrison and full-back Rory Lamont missed training on Sunday, a week before the vital World Cup Pool B clash with Argentina.
Hooker Scott Lawson also missed training, although his calf injury is improving, while Euan Murray was absent due to his religious beliefs.
Morrison starred in the 2-0 Test series win in Argentina in June 2010 and the autumn Tests, but missed the RBS 6 Nations with a knee injury. The Glasgow Warriors centre's absence on Sunday was precautionary due to a slight knee strain, with Lamont resting a tight Achilles.
Scotland will be seeking a sixth straight win and qualification for the quarter-finals with victory over the Pumas following wins over Romania and Georgia.
Scotland captain Alastair Kellock said: "We've got a massive week coming up with the build-up to the Argentina game, we know that.
"But we'll be very focused, we'll work very hard and we'll look to put in a performance to get the win.
"Six in a row would be a great thing, but it's all about winning and getting ourselves into the quarter-finals."